1 #ifndef _X86_64_UACCESS_H
2 #define _X86_64_UACCESS_H
5 * User space memory access functions
7 #include <lwk/compiler.h>
9 #include <lwk/prefetch.h>
11 #include <arch/page.h>
14 #define VERIFY_WRITE 1
17 * The fs value determines whether argument validity checking should be
18 * performed or not. If get_fs() == USER_DS, checking is performed, with
19 * get_fs() == KERNEL_DS, checking is bypassed.
21 * For historical reasons, these macros are grossly misnamed.
24 #define KERNEL_DS 0xFFFFFFFFFFFFFFFFUL
25 #define USER_DS PAGE_OFFSET
27 #define get_ds() (KERNEL_DS)
28 #define get_fs() (current->arch.addr_limit)
29 #define set_fs(x) (current->arch.addr_limit = (x))
31 #define segment_eq(a,b) ((a).seg == (b).seg)
33 #define __addr_ok(addr) (!((unsigned long)(addr) & (current->arch.addr_limit)))
36 * Uhhuh, this needs 65-bit arithmetic. We have a carry..
38 #define __range_not_ok(addr,size) ({ \
39 unsigned long flag,sum; \
40 __chk_user_ptr(addr); \
41 asm("# range_ok\n\r" \
42 "addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \
43 :"=&r" (flag), "=r" (sum) \
44 :"1" (addr),"g" ((long)(size)),"g" (current->arch.addr_limit)); \
47 #define access_ok(type, addr, size) (__range_not_ok(addr,size) == 0)
50 * These are the main single-value transfer routines. They automatically
51 * use the right size if we just have the right pointer type.
53 * This gets kind of ugly. We want to return _two_ values in "get_user()"
54 * and yet we don't want to do any pointers, because that is too much
55 * of a performance impact. Thus we have a few rather ugly macros here,
56 * and hide all the ugliness from the user.
58 * The "__xxx" versions of the user access functions are versions that
59 * do not verify the address space, that must have been done previously
60 * with a separate "access_ok()" call (this is used when we do multiple
61 * accesses to the same area of user memory).
64 #define __get_user_x(size,ret,x,ptr) \
65 asm volatile("call __get_user_" #size \
66 :"=a" (ret),"=d" (x) \
70 /* Careful: we have to cast the result to the type of the pointer for sign reasons */
71 #define get_user(x,ptr) \
72 ({ unsigned long __val_gu; \
74 __chk_user_ptr(ptr); \
75 switch(sizeof (*(ptr))) { \
76 case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
77 case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
78 case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
79 case 8: __get_user_x(8,__ret_gu,__val_gu,ptr); break; \
80 default: __get_user_bad(); break; \
82 (x) = (typeof(*(ptr)))__val_gu; \
86 extern void __put_user_1(void);
87 extern void __put_user_2(void);
88 extern void __put_user_4(void);
89 extern void __put_user_8(void);
90 extern void __put_user_bad(void);
92 #define __put_user_x(size,ret,x,ptr) \
93 asm volatile("call __put_user_" #size \
98 #define put_user(x,ptr) \
99 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
101 #define __get_user(x,ptr) \
102 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
103 #define __put_user(x,ptr) \
104 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
106 #define __get_user_unaligned __get_user
107 #define __put_user_unaligned __put_user
109 #define __put_user_nocheck(x,ptr,size) \
112 __put_user_size((x),(ptr),(size),__pu_err); \
117 #define __put_user_check(x,ptr,size) \
120 typeof(*(ptr)) __user *__pu_addr = (ptr); \
122 case 1: __put_user_x(1,__pu_err,x,__pu_addr); break; \
123 case 2: __put_user_x(2,__pu_err,x,__pu_addr); break; \
124 case 4: __put_user_x(4,__pu_err,x,__pu_addr); break; \
125 case 8: __put_user_x(8,__pu_err,x,__pu_addr); break; \
126 default: __put_user_bad(); \
131 #define __put_user_size(x,ptr,size,retval) \
134 __chk_user_ptr(ptr); \
136 case 1: __put_user_asm(x,ptr,retval,"b","b","iq",-EFAULT); break;\
137 case 2: __put_user_asm(x,ptr,retval,"w","w","ir",-EFAULT); break;\
138 case 4: __put_user_asm(x,ptr,retval,"l","k","ir",-EFAULT); break;\
139 case 8: __put_user_asm(x,ptr,retval,"q","","Zr",-EFAULT); break;\
140 default: __put_user_bad(); \
144 /* FIXME: this hack is definitely wrong -AK */
145 struct __large_struct { unsigned long buf[100]; };
146 #define __m(x) (*(struct __large_struct __user *)(x))
149 * Tell gcc we read from memory instead of writing: this is because
150 * we do not write to any memory gcc knows about, so there are no
153 #define __put_user_asm(x, addr, err, itype, rtype, ltype, errno) \
155 "1: mov"itype" %"rtype"1,%2\n" \
157 ".section .fixup,\"ax\"\n" \
161 ".section __ex_table,\"a\"\n" \
166 : ltype (x), "m"(__m(addr)), "i"(errno), "0"(err))
169 #define __get_user_nocheck(x,ptr,size) \
172 unsigned long __gu_val; \
173 __get_user_size(__gu_val,(ptr),(size),__gu_err); \
174 (x) = (typeof(*(ptr)))__gu_val; \
178 extern int __get_user_1(void);
179 extern int __get_user_2(void);
180 extern int __get_user_4(void);
181 extern int __get_user_8(void);
182 extern int __get_user_bad(void);
184 #define __get_user_size(x,ptr,size,retval) \
187 __chk_user_ptr(ptr); \
189 case 1: __get_user_asm(x,ptr,retval,"b","b","=q",-EFAULT); break;\
190 case 2: __get_user_asm(x,ptr,retval,"w","w","=r",-EFAULT); break;\
191 case 4: __get_user_asm(x,ptr,retval,"l","k","=r",-EFAULT); break;\
192 case 8: __get_user_asm(x,ptr,retval,"q","","=r",-EFAULT); break;\
193 default: (x) = __get_user_bad(); \
197 #define __get_user_asm(x, addr, err, itype, rtype, ltype, errno) \
199 "1: mov"itype" %2,%"rtype"1\n" \
201 ".section .fixup,\"ax\"\n" \
203 " xor"itype" %"rtype"1,%"rtype"1\n" \
206 ".section __ex_table,\"a\"\n" \
210 : "=r"(err), ltype (x) \
211 : "m"(__m(addr)), "i"(errno), "0"(err))
214 * Copy To/From Userspace
217 /* Handles exceptions in both to and from, but doesn't do access_ok */
218 __must_check unsigned long
219 copy_user_generic(void *to, const void *from, unsigned len);
221 __must_check unsigned long
222 copy_to_user(void __user *to, const void *from, unsigned len);
223 __must_check unsigned long
224 copy_from_user(void *to, const void __user *from, unsigned len);
225 __must_check unsigned long
226 copy_in_user(void __user *to, const void __user *from, unsigned len);
228 static __always_inline __must_check
229 int __copy_from_user(void *dst, const void __user *src, unsigned size)
232 if (!__builtin_constant_p(size))
233 return copy_user_generic(dst,(__force void *)src,size);
235 case 1:__get_user_asm(*(u8*)dst,(u8 __user *)src,ret,"b","b","=q",1);
237 case 2:__get_user_asm(*(u16*)dst,(u16 __user *)src,ret,"w","w","=r",2);
239 case 4:__get_user_asm(*(u32*)dst,(u32 __user *)src,ret,"l","k","=r",4);
241 case 8:__get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",8);
244 __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
245 if (unlikely(ret)) return ret;
246 __get_user_asm(*(u16*)(8+(char*)dst),(u16 __user *)(8+(char __user *)src),ret,"w","w","=r",2);
249 __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
250 if (unlikely(ret)) return ret;
251 __get_user_asm(*(u64*)(8+(char*)dst),(u64 __user *)(8+(char __user *)src),ret,"q","","=r",8);
254 return copy_user_generic(dst,(__force void *)src,size);
258 static __always_inline __must_check
259 int __copy_to_user(void __user *dst, const void *src, unsigned size)
262 if (!__builtin_constant_p(size))
263 return copy_user_generic((__force void *)dst,src,size);
265 case 1:__put_user_asm(*(u8*)src,(u8 __user *)dst,ret,"b","b","iq",1);
267 case 2:__put_user_asm(*(u16*)src,(u16 __user *)dst,ret,"w","w","ir",2);
269 case 4:__put_user_asm(*(u32*)src,(u32 __user *)dst,ret,"l","k","ir",4);
271 case 8:__put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",8);
274 __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",10);
275 if (unlikely(ret)) return ret;
277 __put_user_asm(4[(u16*)src],4+(u16 __user *)dst,ret,"w","w","ir",2);
280 __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",16);
281 if (unlikely(ret)) return ret;
283 __put_user_asm(1[(u64*)src],1+(u64 __user *)dst,ret,"q","","ir",8);
286 return copy_user_generic((__force void *)dst,src,size);
290 static __always_inline __must_check
291 int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
294 if (!__builtin_constant_p(size))
295 return copy_user_generic((__force void *)dst,(__force void *)src,size);
299 __get_user_asm(tmp,(u8 __user *)src,ret,"b","b","=q",1);
301 __put_user_asm(tmp,(u8 __user *)dst,ret,"b","b","iq",1);
306 __get_user_asm(tmp,(u16 __user *)src,ret,"w","w","=r",2);
308 __put_user_asm(tmp,(u16 __user *)dst,ret,"w","w","ir",2);
314 __get_user_asm(tmp,(u32 __user *)src,ret,"l","k","=r",4);
316 __put_user_asm(tmp,(u32 __user *)dst,ret,"l","k","ir",4);
321 __get_user_asm(tmp,(u64 __user *)src,ret,"q","","=r",8);
323 __put_user_asm(tmp,(u64 __user *)dst,ret,"q","","ir",8);
327 return copy_user_generic((__force void *)dst,(__force void *)src,size);
332 strncpy_from_user(char *dst, const char __user *src, long count);
334 __strncpy_from_user(char *dst, const char __user *src, long count);
335 __must_check long strnlen_user(const char __user *str, long n);
336 __must_check long __strnlen_user(const char __user *str, long n);
337 __must_check long strlen_user(const char __user *str);
338 __must_check unsigned long clear_user(void __user *mem, unsigned long len);
339 __must_check unsigned long __clear_user(void __user *mem, unsigned long len);
341 __must_check long __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size);
343 static __must_check __always_inline int
344 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
346 return copy_user_generic((__force void *)dst, src, size);
349 #endif /* _X86_64_UACCESS_H */